Recent reporting has zeroed in on the high volume of precision attack and air defence missiles fired by the United States in the war against Iran over the last two weeks. Apart from a focus on the unfavourable cost comparison between inexpensive Iranian drones and costly US interceptors — a ratio as dire as 1:200 —commentators have also highlighted the risks that a protracted campaign against Iran could undercut America’s preparedness for a potential high-end conflict in Asia.
The reality, however, is that the campaign against Iran is but the latest episode in a series of Middle East operations since 2016, but particularly since 2022, that have taxed US military readiness and strained already low stockpiles of both offensive and defensive munitions that would be essential to any prospective high-end conflict in the Indo-Pacific. In our March 2025 report Federation is deterrence: The US defence industrial and technology integration agenda in the Indo-Pacific, USSC non-resident fellow Sophie Mayo and I showed how “unanticipated and increasingly protracted military operations” in the Middle East in the preceding three years had put further pressure on a defence industrial base already stretched by competing global security commitments, growing demand from US allies and partners around the world, and historical maintenance and production backlogs that remained unaddressed. Those problems are only magnified by the Iran campaign.
With respect to munitions in particular, the problem has been as much a failure to anticipate the scale of future demands as it has been to replenish depleted inventories. For instance, the number of Tomahawk land attack missiles fired by the US Navy in the opening days of operations against the Houthis in December 2023 amounted to 145% of missiles procured in the previous financial year, while the Pentagon replaced only 80% of the 125 Tomahawks used in its 2017-2018 strike campaigns against Syrian Government targets in the department’s 2018 and 2019 budgets. Procurement of missile interceptors has spiked in the aftermath of unexpected military operations, only to seemingly return to business-as-usual rates in the years thereafter. The result is that at the moment of greatest urgency, American inventories are low.
There are plans to increase US production capacity for long-range strike weapons and missile interceptors to replace used munitions and to get ahead of future demands, but these will take years to reach completion. Several strategic framework agreements between the White House and US defence primes over the last two years have focused on greatly expanding production for exactly the sorts of precision missiles and interceptors being exhausted in the conflict with Iran, including many models which Australia is also seeking to buy. Some of these munitions, like the PAC-3 interceptor, had already been the subject of production expansion initiatives since Russia invaded Ukraine in February 2022. Others, like the Precision Strike Missile and Standard Missile 3, have only recently been combat-proven and their recent expenditure and forecast production rates are less apparent from public information. In any case, the expansion of existing factories, let alone the construction of new facilities, will likely take several years to complete, and there are few specific timelines for when projected increases in missile production are likely to hit their peak.
In any case, the delta between current usage and replenishment rates of US weapons against Iran has at least two major implications. Firstly, it raises questions about the Trump administration’s discipline in appropriately resourcing its avowed global security priorities, considering that the National Security Strategy and National Defense Strategy each seemingly deprioritised the Middle East in favour of a focus on the Western Hemisphere and the Indo-Pacific. Indeed, the vast majority of long-range weapons and interceptors employed against Iran to date are just as vital to deterrence and warfighting requirements in the Indo-Pacific — and, as experts from the Center for a New American Security recently pointed out, the United States “has never had sufficient stockpiles for a high-intensity fight with a near-peer adversary like China.” Given the timelines for replenishing stockpiles for these systems, let alone meeting spiking global demands for air defences and strike systems, the United States and its allies in Asia are facing an even more acute shortages of high-end air defences and long-range strike missiles in what many believe to be the window of highest risk of a potential major Chinese military move against Taiwan.
Secondly, the war against Iran could also delay allied access to these same systems and further incentivise these countries to look to alternative suppliers. In Europe, for instance, there are already fears that this latest snap shortage in PAC-3 missiles will only accentuate the already unfavourable supply-and-demand situation for high-end air defences in Ukraine and delay deliveries to other frontline partners like Poland. That could reinforce a prevailing trend amongst many US partners in Asia, Europe and the Middle East looking to diversify their sources of military hardware away from American hardware, much of which takes many years to deliver. For instance, several Middle Eastern countries were already major customers of South Korean defence companies, whose mid-range missile interceptor capabilities have reportedly proven very effective in countering Iranian drone and missile attacks for a fraction of the cost — and delivery within a fraction of the time — that it presently takes to produce and procure a US Patriot system.
A more diversified international arms market could undercut the Administration’s emphasis on Foreign Military Sales both as a key foreign policy lever and as a means of rebuilding American manufacturing capacity at home, though it could also force the US to look more seriously to allies like Australia and Japan to supplement its missile production capacity.
